diff --git a/CMakeLists.txt b/CMakeLists.txt
index b4c77ea..f687f04 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: MIT
 cmake_minimum_required (VERSION 3.11)
 
 project(kcron C)
diff --git a/src/C/CMakeLists.txt b/src/C/CMakeLists.txt
index 2c7e7f3..6022dab 100644
--- a/src/C/CMakeLists.txt
+++ b/src/C/CMakeLists.txt
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: MIT
 cmake_minimum_required (VERSION 3.14)
 
 #############################
diff --git a/src/C/autoconf.h.in b/src/C/autoconf.h.in
index 30f5a23..acf8497 100644
--- a/src/C/autoconf.h.in
+++ b/src/C/autoconf.h.in
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: MIT */
 /*
 
    Copyright 2023 Fermi Research Alliance, LLC
diff --git a/src/C/client-keytab-name.c b/src/C/client-keytab-name.c
index a7f6784..95c4b32 100644
--- a/src/C/client-keytab-name.c
+++ b/src/C/client-keytab-name.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: MIT */
 /*
  *
  * A simple program that prints the path to the user's client keytab file.
diff --git a/src/C/create-empty-client-keytab.c b/src/C/create-empty-client-keytab.c
index 1f2b9ac..d3d8960 100644
--- a/src/C/create-empty-client-keytab.c
+++ b/src/C/create-empty-client-keytab.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: MIT */
 /*
  *
  * A simple program that creates an empty client keytab file.
diff --git a/src/C/init-kerberos-client-dir.c b/src/C/init-kerberos-client-dir.c
index efee8b1..edae75c 100644
--- a/src/C/init-kerberos-client-dir.c
+++ b/src/C/init-kerberos-client-dir.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: MIT */
 /*
  *
  * A simple program that generates a blank keytab in a deterministic location.
diff --git a/src/C/kcron_caps.h b/src/C/kcron_caps.h
index 4868bfa..06d49a7 100644
--- a/src/C/kcron_caps.h
+++ b/src/C/kcron_caps.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: MIT */
 /*
  *
  * A simple place where we keep our CAPABILITIES(7) calls
diff --git a/src/C/kcron_empty_keytab_file.h b/src/C/kcron_empty_keytab_file.h
index c4401f4..679e2e9 100644
--- a/src/C/kcron_empty_keytab_file.h
+++ b/src/C/kcron_empty_keytab_file.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: MIT */
 /*
  *
  * Functions for writing empty keytab file headers
diff --git a/src/C/kcron_filename.h b/src/C/kcron_filename.h
index 366f38c..ecbdf5f 100644
--- a/src/C/kcron_filename.h
+++ b/src/C/kcron_filename.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: MIT */
 /*
  *
  * Filename and path handling functions for kcron keytabs
diff --git a/src/C/kcron_landlock.h b/src/C/kcron_landlock.h
index 2a2dbc9..f1ebeb2 100644
--- a/src/C/kcron_landlock.h
+++ b/src/C/kcron_landlock.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: MIT */
 /*
  *
  * Landlock filesystem access control for kcron
diff --git a/src/C/kcron_seccomp.h b/src/C/kcron_seccomp.h
index 0bee173..a2cc59c 100644
--- a/src/C/kcron_seccomp.h
+++ b/src/C/kcron_seccomp.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: MIT */
 /*
  *
  * Seccomp syscall filtering for kcron
diff --git a/src/C/kcron_setup.h b/src/C/kcron_setup.h
index b80925d..0e30f24 100644
--- a/src/C/kcron_setup.h
+++ b/src/C/kcron_setup.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: MIT */
 /*
  *
  * Runtime hardening setup functions including ulimits, seccomp, and landlock
diff --git a/src/shell/CMakeLists.txt b/src/shell/CMakeLists.txt
index fd45542..f18b09e 100644
--- a/src/shell/CMakeLists.txt
+++ b/src/shell/CMakeLists.txt
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: MIT
 cmake_minimum_required (VERSION 3.11)
 
 include(GNUInstallDirs)
diff --git a/src/shell/kcron.sysconfig b/src/shell/kcron.sysconfig
index a9e09d8..732ab08 100644
--- a/src/shell/kcron.sysconfig
+++ b/src/shell/kcron.sysconfig
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: MIT
 ###########################################################
 # Default settings for kcron
 ###########################################################
diff --git a/src/shell/kcrondestroy b/src/shell/kcrondestroy
index cd0b23b..126cd23 100644
--- a/src/shell/kcrondestroy
+++ b/src/shell/kcrondestroy
@@ -1,4 +1,5 @@
 #!/bin/bash -u
+# SPDX-License-Identifier: MIT
 
 ###########################################################
 if [[ -r /etc/sysconfig/kcron ]]; then
diff --git a/src/shell/kcroninit b/src/shell/kcroninit
index 4ab59c1..8af809d 100644
--- a/src/shell/kcroninit
+++ b/src/shell/kcroninit
@@ -1,4 +1,5 @@
 #!/bin/bash -u
+# SPDX-License-Identifier: MIT
 
 ###########################################################
 if [[ -r /etc/sysconfig/kcron ]]; then